package cn.newtouch.service.account;

import java.util.Set;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.dao.DataAccessException;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.GrantedAuthorityImpl;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.core.userdetails.UsernameNotFoundException;
import org.springframework.transaction.annotation.Transactional;

import cn.newtouch.entity.account.Authority;
import cn.newtouch.entity.account.Role;
import cn.newtouch.entity.account.User;

import com.google.common.collect.Sets;

/**
 * 实现SpringSecurity的UserDetailsService接口,实现获取用户Detail信息的回调函数.
 * 
 * @author calvin
 */
@Transactional(readOnly = true)
public class UserDetailsServiceImpl implements UserDetailsService
{

    private AccountManager accountManager;

    /**
     * 获取用户Details信息的回调函数.
     */
    public UserDetails loadUserByUsername(String username)
            throws UsernameNotFoundException, DataAccessException
    {

        User user = this.accountManager.findUserByLoginName(username);
        if (user == null)
        {
            throw new UsernameNotFoundException("用户" + username + " 不存在");
        }

        Set<GrantedAuthority> grantedAuths = this
                .obtainGrantedAuthorities(user);

        // -- miniweb示例中无以下属性, 暂时全部设为true. --//
        boolean enabled = true;
        boolean accountNonExpired = true;
        boolean credentialsNonExpired = true;
        boolean accountNonLocked = true;

        UserDetails userdetails = new org.springframework.security.core.userdetails.User(
                user.getLoginName(), user.getPassword(), enabled,
                accountNonExpired, credentialsNonExpired, accountNonLocked,
                grantedAuths);

        return userdetails;
    }

    /**
     * 获得用户所有角色的权限集合.
     */
    private Set<GrantedAuthority> obtainGrantedAuthorities(User user)
    {
        Set<GrantedAuthority> authSet = Sets.newHashSet();
        for (Role role : user.getRoleList())
        {
            for (Authority authority : role.getAuthorityList())
            {
                authSet.add(new GrantedAuthorityImpl(authority
                        .getPrefixedName()));
            }
        }
        return authSet;
    }

    @Autowired
    public void setAccountManager(AccountManager accountManager)
    {
        this.accountManager = accountManager;
    }
}
